The prices of several other varieties of Malaysian vegetables are also up as a result of the north-east monsoon arriving early and wrecking harvests.

At some wet markets, customers are paying about $10 a kilogram for green and red chillies, double the price two months ago.

Wet-market stall owners The Straits Times spoke to say chilli prices are the highest in at least 10 years.

Another Malaysian-grown vegetable that has become more costly in the last two months is Chinese lettuce. Wet markets now charge $6 a kilogram for it, up from $4.

Spring onions are now tagged at $8 a kilogram, up from $5, and old cucumbers have jumped from $2.80 to $3.50 a kilogram. The prices of leafy vegetables such as cai xin and kai lan have also gone up by about $1 in the last two months to $2.50 a kilogram.

The persistent wet weather has caused Malaysian vegetable harvests to rot, and the resulting short supply is sending prices up, say importers here.

The wet weather looks set to continue into January, said the weatherman here of the monsoon, which brings moderate to heavy rain lasting a few days to Peninsular Malaysia and Singapore.

Singapore Fruits and Vegetables Importers and Exporters Association chairman Tay Khiam Back said: 'Leafy vegetables and chillies are grown outdoors and are easily destroyed by heavy rain. They get rotten before they are harvested.'

Vegetables grown in greenhouses, such as tomatoes, eggplants and capsicums, are unaffected, he added.

Wet-market vegetable stall owners like Mr Jimmy Koh are feeling the pain. The owner of a stall in Serangoon Gardens wet market has been dumping about half a kilogram of rotten Malaysian chillies daily, an eighth of what he buys.

While some greens rot even before they leave the farms and are not brought in here, some start to go bad en route but are sold anyway to importers like Mr Koh.

Tagging the remainder of his stock at $9.50 a kilogram yesterday, he said: 'Last time, we never had to throw any away.'

Wholesalers are, in the meantime, turning to alternative sources.

Mr Gary Ong, 42, who owns Vat Thoa Vegetables Wholesaler, now brings in 700kg of China chillies daily, up from none two months ago. He has cut back on his imports of the Malaysian variety from 740kg daily two months ago to about 350kg.

He explained that the China variety is in abundant supply and can be sold at half the price of the Malaysian type.

'We still need to supply the same amount, and some clients who buy in bulk demand low prices,' he said.

He added, however, that the demand for Malaysian chillies is still brisk because they are hotter and look better than the Chinese ones.

Consumers like Madam Lim Sok Hwa, 51, are doing without Malaysian chillies for now.

She said: 'What's the point buying the ones from China? They are not spicy enough anyway.'

limjess@sph.com.sg